Expression patterns of AMPK and genes associated with lipid metabolism in newly hatched chicks during the metabolic perturbation of fasting and refeeding.

Fasting-refeeding perturbation has been extensively used to reveal specific genes and metabolic pathways that control energy metabolism in chickens. In this study, 200 chickens were randomly assigned to 2 groups after hatching: the control group (C, fed ad libitum) and the fasting-refeeding group (T, water ad libitum). The chicks in Group T were fasted for 72 h, and then fed for another 48 h. Liver, hypothalamus, and adipose samples were collected at 0 (F0), 24 (F24), 48 (F48), and 72 h (F72) after fasting and 4 (FR4), 12 (FR12), 24 (FR24), and 48 h (FR48) after refeeding, respectively. Results showed that Group T had a significantly higher number of liver vacuoles (P < 0.05 or P < 0.01) and a significantly lower gray value of Sudan IIIstained sections (P < 0.05 or P < 0.01) than Group C at F48-FR48. In addition, compared with the Group C, fasting and refeeding reduced the expression of stearoyl CoA desaturase (SCD) mRNA (P < 0.05 or P < 0.01) in the liver and adipose tissues, the expression of glucocorticoid receptor (GR) mRNA (P < 0.05 or P < 0.01) in the liver, adipose, and hypothalamus tissues, and the expression of fatty acid synthase (FAS) mRNA (P < 0.05 or P < 0.01) in the liver at F24-FR24. Moreover, relative to those in Group C, fasting and refeeding increased the mRNA expression levels of adenosine monophosphate-activated protein kinase (AMPK) α, AMPKß, and AMPKγ in the hypothalamus (P < 0.05 or P < 0.01) at F24-FR24. In conclusion, fasting and refeeding increased the fat content of the liver, and the expression of lipolytic genes in the hypothalamus (e.g., AMPKα, AMPKß, and AMPKγ) but decreased the expression of fat synthesis genes in the liver (e.g., SCD, GR, and FAS), adipose (SCD and GR), and hypothalamus (GR).

Astragalus polysaccharide alleviates transport stress-induced heart injury in newly hatched chicks via ERS-UPR-autophagy dependent pathway.

Transport stress (TS) not only affects animal welfare but also eventually leads to higher morbidity and mortality. Moreover, TS could induce heart injury in animals, but the possible mechanism has yet to be fully explored. Astragalus polysaccharide (APS) is a main active component of Radix Astragali, which has an extensive anti-stress effect. However, the effect of APS on TS-induced heart injury has not yet been elucidated. In this study, a chick model of simulated TS was used. 240 newly hatched chicks were arranged into 4 groups: Control (Con), Transport group (T), Transport + water group (TW), and Transport + APS group (TA). Before transport, the chicks of the TW and TA groups were treated with deionized water and APS (0.25 mg/mL, 100 µL) by oral drops respectively. The histopathological analysis of myocardial tissue was assessed by hematoxylin and eosin staining. qRT-PCR and Western Blotting assays were employed to measure the expression of genes and proteins. Semiquantitative PCR was performed for the X box-binding protein-1 (XBP-1) mRNA splicing assay. The results indicated that APS significantly reduced TS-induced myocardial histopathological changes. Meanwhile, TS induced endoplasmic reticulum stress (ERS), evidenced by an activation of the unfolded protein response (UPR) signaling pathway and up-regulation of ERS-markers (P < 0.05). Moreover, TS markedly triggered autophagy induction by activating AMP-activated protein kinase (AMPK), reflected by augmented LC3-II/LC3-I, AMPK phosphorylation and autophagy-related genes (ATGs) expression (P < 0.05). Importantly, our study manifested that treatment of APS could reduce TS-induced ERS and AMPK-activated autophagy, accordingly alleviating heart injury of transported chicks. In summary, these findings indicate that TS induces heart injury in chicks via an ERS-UPR-autophagy-dependent pathway, and APS as an effective therapeutic method to alleviate it.

Nutrition and Digestive Physiology of the Broiler Chick: State of the Art and Outlook.

Because the intestine is the primary nutrient supply organ, early development of digestive function in newly hatched chick will enable it to better utilize nutrients, grow efficiently, and achieve the genetic potential of contemporary broilers. Published data on the growth and digestive function of the gastrointestinal tract in neonatal poultry were reviewed. Several potential strategies to improve digestive tract growth and function in newly hatched chick are available and the options include breeder nutrition, in ovo feeding, early access to feed and water, special pre-starter diets, judicious use of feed additives, and early programming.

Effect of a commercial product containing canthaxanthin for in ovo feeding to broiler embryos on hatchability, chick quality, oxidation status, and performance.

In ovo feeding has been indicated to improve hatchability, newly hatched chick quality, and broiler performance. The aim of this study was to investigate the effect of in ovo feeding of a commercial canthaxanthin product (CCX) containing lignosulphonate, corn starch, canthaxanthin, dextrin (yellow), and ethoxyquin through assessing incubation results, newly hatched quality and oxidation status and broiler performance at 1 to 14 d of age. A total of 780 egg were distributed in a randomized complete block design with 5 treatments (levels of CCX: 0.0, 0.35, 0.45, 0.55, and 0.65 mg/0.5 mL of sterilized and distilled water) and 156 eggs per treatment. The blocking factor was setters. At 17.5 d of embryo development, in ovo injected treatments were applied, using a manual needle. The in ovo feeding of CCX resulted in lower hatching rates (P < 0.05) and a longer hatching window (P < 0.05) as compared with noninjected CCX treatment. The CCX injection did not affect the bursa and spleen percentage of newly hatched chick (P > 0.05). In addition, a higher percentage of chicks with poor physical quality score (<71.0 points) was obtained among the chicks from eggs injected with 0.55 and 0.65 mg of CCX (P < 0.05). There were higher total proteins and catalase activity in the livers of the chicks injected with CCX. Broiler chicks in the control group (0.0 mg of CCX) presented higher BW and BW gain during 1 to 7 and 7 to 14 d of after hatch (P < 0.05). The viability (%) of chicks at 1 to 14 d of after hatch decreased with inoculation greater than 0.45 mg of CCX in ovo (P < 0.05). Although the CCX shown an improvement in oxidation status of chicks, the hatchability and performance of broilers decreased. We concluded that a commercial CCX is not recommended for injection in ovo, and furthers studies should carried out to elucidate the use of pure canthaxanthin.

Embryonic Exposure to Valproic Acid Affects Social Predispositions for Dynamic Cues of Animate Motion in Newly-Hatched Chicks.

Early predispositions to preferentially orient toward cues associated with social partners have been documented in several vertebrate species including human neonates and domestic chicks. Human newborns at high familiar risk of Autism Spectrum Disorder (ASD) show differences in their attention toward these predisposed stimuli, suggesting potential impairments in the social-orienting mechanisms in ASD. Using embryonic exposure to valproic acid (VPA) we modeled ASD behavioral deficits in domestic chicks. To investigate social predispositions toward animate motion in domestic chicks, we focused on self-propulsion, using two video-animations representing a simple red circle moving at constant speed (speed-constant) or one that was changing its speed (accelerating and decelerating; speed-change). Using a spontaneous choice test for the two stimuli, we compared spontaneous preferences for stimuli that autonomously change speed between VPA- and vehicle-injected chicks. We found that the preference for speed changes was abolished in VPA-injected chicks compared to vehicle-injected controls. These results add to previous findings indicating similar impairments for static social stimuli and suggest a specific effect of VPA on the development of mechanisms that enhance orienting toward animate stimuli. These findings strengthen the hypothesis of an early impairment of predispositions in the early development of ASD. Hence, early predispositions are a potentially useful tool to detect early ASD symptoms in human neonates and to investigate the molecular and neurobiological mechanisms underlying the onset of this neurodevelopmental disorder.